Well, that is helpful, at age 22 she was already married and native of Mississippi as were her parents, possibly of Tunica Co.
Theory says if she was about 22 in 1920, she was about 12 in the 1910 and about 2 in the 1900
And the quest is to find her maiden surname and her maiden family ...
There's three places I can think of to discover her maiden surname and that would be on the birth/death records of two or more of her children; on the marriage license/record of her marriage; and on her own death record
Well, there's a 4th, not quite as reliable -- when there is a sibling of Clara living with Willie and Clara 1920, 1930, 1940 ... could turn out to be a half-sib of Clara and if they only shared the mother, the surname could easily differ. In some cases you might discover the mother had three or four different men in her life and children by each so there's more than one surname among the children
Ha. Sometimes a sibling with a different surname is the first clue you have that their mother was married / allied more than once. You find out that sort of thing about the father when you track the various siblings death records and find they don't all have the same mother, even though these sibs all had the same surname.
Now, since you say you do not have her maiden surname, LNAB, I have to suppose you do not have any of the three pieces of paper I mentioned ... her full marriage license/ceremony record, her birth / death record, or that of two or more of her children?
Admittedly, there could be five children, and you can get the death records of all five and 2 won't have the mother's name on it, and the other three don't agree on her surname. I've had that happen.
There are times when you just have to keep collecting documents until you can get what amounts to a consensus among them about the probable name and even then you can't be 100% certain